An independent study of 18 FDA-approved mHealth devices that measure blood glucose in diabetic users has found that two-thirds aren't accurate, potentially putting the user at risk.

August 24, 2017 - An independent study of 18 popular mHealth sensors used by people with diabetes finds that two-thirds aren’t meeting standards for accuracy, potentially putting those users at risk.

The analysis of 18 FDA-approved blood glucose monitoring systems (BGMSs) by the Diabetes Technology Society found that only six meters recorded blood glucose levels within 15 percent of mg/dl of the laboratory value in at least 95 percent of the tests. In layman’s terms, this means a person with diabetes can be confident that a blood glucose reading is accurate 19 times out of 20.

Those falling below the threshold were accurate between 71 percent and 92 percent of the time.

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The meters represent 90 percent of the commercially available digital health devices used by those with diabetes between 2013 and 2015, the study reported. Those tested were developed by Bayer, Roche, Arkray, Agametrix, Abbott, LifeScan, Prodigy, Omnis Health, HDI/Nipro, BioSense Medical, Diabetic Supply of Suncoast and Philsys.

Conducted by a team of researchers led by David C. Klonoff, MD, of the Diabetes Research Institute at San Mateo, Calif.-based Mills-Peninsula Medical Center and funded by Abbott, the study used BGMSs bought in retail locations and tested on more than 1,000 people in three labs.

Researchers said the results could be especially important to the Medicare community – federal statistics show that almost 70 percent of Medicaid mail-orders for BGMSs in 2016 involved meters that didn’t pass the study’s accuracy standards. Inaccurate blood-glucose readings could have a significant effect on a patient’s health and the cost to provide chronic care management.

They also noted that DTS standards are more stringent than those used by the U.S. Food and Drug Administration. According to FDA guidance published in late 2016, over-the-counter devices must be within 15 percent of true value (lab measurement) 95 percent of the time and within 20 percent of the true value 20 percent of the time.

According to the online resource HealthLine, diabetes advocates and patients “have been voicing concerns about inaccuracy for more than a decade,” leading the FDA to launch a program to update those guidelines in 2014.

"Based on feedback received from manufacturers, increasing the accuracy of [BGMSs] too much would increase their costs while reducing their availability to patients," FDA spokeswoman Stephanie Caccomo told Healthline in an October 2016 story. "Patient feedback indicated that they did not want reduced device usability (from increased testing time, increased sample volume, etc.) in order to maintain consistent pricing for strips where the accuracy has been increased substantially."

"[T]his represents a significant accuracy improvement compared to meters marketed even five years ago," Caccomo said, adding the FDA believes many of the meters already on the market today should be able meet the improved standards.

Diabetes affects some 29 million people in the US (almost 10 percent of the population), with another 86 million, or one in three adults, having blood sugar levels that trend toward the chronic disease. And both of those numbers are growing steadily.

Among the latest developments are BGMs that automatically track and send blood glucose readings to a user’s smartphone or web portal, then on to a healthcare provider through the cloud. Analytics and even machine learning technology can now track those readings to detect trends, alerting caregivers and users when a medical emergency is imminent.

The online website diaTribe noted that the FDA has been cracking down on inaccurate BGMs over the past few years: 61 meters were cleared in 2012, but only 35 were approved in 2015 and only about 20 were approved in 2016.